This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-262948, filed Aug. 31, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a portable information apparatus that incorporates a radio communication antenna and, more particularly, to a notebook type personal computer that incorporates a radio communication antenna.
2. Description of the Related Art
Conventionally, notebook type personal computers (to be referred to as notebook PCs hereinafter) that incorporate radio communication antennas have been developed. For example, a notebook PC disclosed in U.S. Pat. No. 5,677,698 realizes a compact antenna built-in type notebook PC by attaching two slot antennas to the back surface side of its liquid crystal display. Also, this notebook PC adopts a diversity wireless LAN system, which mounts two antennas.
However, according to the technique disclosed in U.S. Pat. No. 5,677,698 as the prior art, a size reduction is achieved using a dielectric case. However, since the antennas require a large area, they are mounted on the back surface side of a housing of the liquid crystal display. Hence, the antennas radiate strongly on the back surface side of the liquid crystal display but less on the front surface side.
In recent years, a new short-range radio communication scheme Bluetooth has been developed, and many antennas are mounted to use a plurality of radio communication schemes.
For example, a combination of 802.11b wireless LAN and Bluetooth using the identical 2.4-GHz band, and a combination of the future 802.11a wireless LAN using the 5-GHz band and Bluetooth in future may be used.
However, commercially available notebook PCs having radio communication functions incorporate a single wireless LAN communication function, PHS communication function, or the like alone.
Therefore, when antennas compatible to these radio communication functions are mounted on a conventional notebook PC, interference among antennas and a reduction of the effect of the diversity antenna may occur.
The present invention has been made in consideration of the above situation, and has as its object to provide a portable information apparatus which can mount a plurality of antennas compatible to a plurality of radio communication schemes, and incorporates radio communication antennas that can obtain radiation characteristics with good balance on both the front and back surface sides of the portable information apparatus.
Therefore, according to the first aspect of the present invention, a portable information apparatus comprises a main body of the portable information apparatus, a display unit attached to the main body of the portable information apparatus, a plurality of radio communication diversity antennas provided to the display unit, and a radio communication antenna which is provided to the display unit at a position between at least one pair of radio communication diversity antennas of the plurality of radio communication diversity antennas.
According to this invention, high radiation performance of the radio communication antenna can be educed, and the influences of fading on the diversity antennas can be reduced.
According to the second aspect of the present invention, in the first aspect, the display unit comprises a liquid crystal panel, and a housing fixing the liquid crystal panel, the plurality of radio communication diversity antennas are respectively attached to a plurality of first antenna boards, and the radio communication antenna is attached to a second antenna board, and the plurality of first antenna boards and the second antenna board are respectively attached to the housing on the back surface side of the liquid crystal panel with the plurality of radio communication diversity antennas and the radio communication antenna being located on an upper portion of the liquid crystal panel to be separated by a predetermined spacing.
According to this invention, the plurality of radio communication diversity antennas and radio communication antenna can have substantially uniform radiation characteristics on the front and back surface sides of the display unit.
Furthermore, according to the third aspect of the present invention, a portable information apparatus comprises a main body of the portable information apparatus, a display unit attached to the main body of the portable information apparatus, diversity antennas provided to the display unit and including at least two antennas, a first radio communication unit, connected to the diversity antennas, making a communication by a first radio communication scheme using a diversity function, a second radio communication unit, connected to one of the at least two antennas, making a communication by a second radio communication scheme different from the first radio communication scheme, and a switching unit switching the first and second radio communication units.
According to this invention, a plurality of radio communication schemes can be used by a fewer number of antennas, and a low-cost, compact notebook PC can be provided.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.